Hi njc23,
Thank you for your further question.
We would advise you that you can only complete an NRL1 registration form up to 3 months before you plan to leave the UK.
We would suggest that you contact our Non Resident Landlord (NRL) scheme helpline for more information in repect of your question regarding the timescale for an application and the length of time your application will take to deal with.
Please see their contact details in the following link :
Non-UK resident landlords
We would also advise you that in respect of a jointly owned property with your wife you would both need to complete an individual NRL1.
Thank you.